Random numbers are useful for a variety of purposes such as generating encrypted data and modeling complex phenomena. True random number generators tend to use atmospheric noise to generate data.
In magnetism, a domain wall (DW) is an area of gradual transition from a magnetic moment of one orientation to another. The motion of domain walls (DWs) using a technique known as spin transfer torque (STT) has paved the way for research into non-volatile magnetic memories and logic devices. The technique presently used to inject DWs into such systems utilises a localised Oersted field generated by passing a current through a metallic strip-line. However, this DW generation process is deterministic and therefore not suitable for use in a random number generator.
Recently a magnetic structure was proposed in which thermal energy was utilized to nucleate DWs. An in-plane current was passed through a nanowire to generate joule heating to trigger DW nucleation. However, a magnetic field was also applied to assist the DW nucleation and magnetization reversal. However, this reversal process is not stochastic and thus cannot be employed in a random number generator application. Furthermore, the generation of a magnetic field may not be suitable for on-chip device applications.
It is therefore an aim of the present invention to build on the above to provide a magnetic random number generator.